Hi I was wondering if anyone knows of a good tutorial on how to replace a mast track on a board? Or if anyone has any advice they'd like to share.

Thanks!!!

Buy mast box, about 20 bucks.
Rout out old one, leaving 1/2" more around perimeter. Depth 1/8" deeper than new box.
Drop new box in with epoxy resin. Cavity filled with 2 layers 8 oz cloth.

Do I glass over the box or do I press the glass down under the box?

Glass over is a separate step.

Above is the easy version.
However- has the track sunk (can you push up and down and get movement?) If so the foam underneath is trashed and it needs a lot more work. This will be routing out way bigger and fitting a PVC foam / corecell block then routing for the track install.

Is it just leaking from a little crack where the top glass has come away? Totally different and easier

I would rout out old box .
Roughly gouge out foam an inch or so , wider longer and deeper than the box under the existing board laminate .
Fill with 80 kg pour foam . ( can use expanda foam in a can but it's not as good ) . It will expand out the hole like a mushroom so mask off area . With a hacksaw blade cut flush with board and sand flat .
Re rout hole in new foam to box size .
Fill mast track box slot with jammed in polystyrene foam and sand flat .
Glue in mast box with slightly thickened resin . Some people like to make board hole a little bigger and lign with glass before pushing in box . One or two mm bigger than box , not half inch .
When cured sand box flush with board . Sand area 7cm wider and longer than box through deck grip and paint to the glass , ( carbon ) , layers . Don't go through the layers .
I would laminate five layers of 4oz or four layers 6 oz glass over the top of the box . First layer 3cm bigger than box , second 4 cm , third 5 cm fourth 6 cm.
Sand high spots .
Fill with resin bog , sand , paint and re grip over area .
Lastly cut out the mast track slot . It's easy , drill a few small holes and with a hacksaw blade and file , can do a neat job . To find the box slot , mark lines with pencil outside the repair area before doing all of the above .
Have fun , it's not that hard .

I always put at least 1 x 6oz around the box after buttering it, then more buttering.
after insertion, some glass is poking up around the entire perimeter and sanded off. That then bonds to the deck laminate.
Then, it takes a sh!!!teload more force to sink that box, all the fibres are in tension and won't break unlike the resin and filler mix that can fracture

Thanks everyone for the replies.

The board currently has a 340mm x 130mm hole cut in the deck and filled with what looks like expanda foam.
Yes everything is easy once you do it a couple times. Like they say in medical school watch one, do one, teach one. Unfortunately, I just have to go straight to doing one.

I was given a harder foam block. I'm not sure what the material is but I was told that I should use that to house the mast track as the expanda foam isn't strong enough.

This is my current plan of attach.

1. Cut off expanda foam with a hack saw blade.
2. Sand flat.
3. Some places are still a low ( 5 mm or so) so I'll put a little more expand foam, cut and sand again.
4. Route out area the size of hard foam block.
5. Sand deck 5 cm from cut out.
6. Tape area 5 cm around cut out and protect rest of deck with plastic.
7 Cut carbon fibre cloth to the size needed.
8. Wet carbon fibre cloth with epoxy resin and line hole that I just routed and push in with hard foam block so the foam block is 2 mm below the deck. This is a step I am not sure of. Does the cloth go in the hole and line the sides and bottom? Or just on top of the inserted foam.
9. Fill any gaps with epoxy resin mixed with q-cell.
10. Smooth out any air bubbles.
11. Wrap tight with plastic wrap and place old wetsuit on to and sand bags on top of that.
12. When dry remove plastic and sand smooth.
13. Route hole in foam block the size of mast track.
14. Wet carbon fibre cloth with epoxy resin and line hole that I just routed and push in with mast track so the mast track is 2 mm below the deck. Again this is a step I am not sure of. Does the cloth go in the hole and line the sides and bottom? Or just on top of the mast track.
15. Smooth out any air bubbles.
16. Wrap tight with plastic wrap and place old wetsuit on to and sand bags on top of that.
17. Laminate 3 layers of carbon fibre on top of the mast track and area deck cut out. Wrapping and using sand bags to squeeze out air.

How does that sound?

PM sent - you're close but overthinking it a bit

yep, 2mm is way to much! It takes about 10 layers of 6oz cloth to make 2mm. The only time I'd leave a big gap, is if I'm going to recreate the deck sandwich, and then it would be a tad over 3mm. But you shouldn't need that with a high density block there. what size is your hard block? It's not going to be much good if it's close to the size of the mast track.

The hard block is about the same size as the mast track but I was going to glass/epoxy them together before inserting them.

I don't want to do 10 layers of glass so I will keep around 1 mm.

Block needs to be at least 50mm longer and 10mm wider than the track. Pref about 230 x 50 x 40thick for a normal length (non-vented) track
You can make it bigger by laminating strips of PVC foam on with resin/q-cell mix

okay. Thanks everyone, I think I have a game plan now. I just have to source the carbon cloth. Epoxy I should be able to get here in Margaret River.

No need for carbon. You want some amount, however little, of flex to absorb shock for durability.
Mixing carbon with cloth not a great idea.

Agreed. Just glass mate,
2 x 4oz around the track is fine.

4 x 4oz over the top afterwards

You will be able to get all you need as offcuts at Delta

Looking good, great job

Thought I would ask the question here due to the experienced hands and since I am in lock down.

My 1st board attempt its Paulownia over EPS so have zero experience.

Put the leash and fin boxes in then just touched up with some epoxy. Sanded then cleaned all the areas with mentholated spirts before apply the epoxy and used gloves to avoid finger prints. Mixed exactly 2:1.

The epoxy turned out as below (orange peel like) which I just sanded a touch so the problem stands out. I didn't add any additive "F" (don't have any)

Is this the fish eye problem talked about or have I made a mistake? Its the same in all areas I applied to.

Also do I have to sand right back or would a filler / hot coat cover?

Appreciate any advice.

Its the cleaning of it sorry to say. Nothing touches board between lam and hotcoat,...... and that why pre-glass boxes like FCS2 and Futures are so much easier.
That is easily saved though, another hotcoat will fill those low spots you will just be sanding for 10x longer.
80 grit on a machine sander to start with

Select to expand quote

Mark _australia said..
Its the cleaning of it sorry to say. Nothing touches board between lam and hotcoat,...... and that why pre-glassboxes like FCS2 and Futures are so much easier.
That is easily saved though, another hotcoat will fill those low spots you will just be sanding for 10x longer.
80 grit on a machine sander to start with

Thanks Mark

Thanks to everyone that replied. It was a huge help. I think everything went more or less ok for a first go. The expands foam seems a little too weak and a stronger foam would probably be the way to go. I put a layer of resin/Q-cell over the expanda foam so it was flat for the glass to go on. Only time on the water will tell how it really went.

My question now is can I paint it? If so what kind of paint should I use? And after painting can I do the gripping with resin and sugar?

Hardware store acrylic spray paint can. 6 bucks.

Resin and salt.

Don't paint yet -
Is that white bit the expanding foam?If so you may have an issue. We were talking about replacing all that with a big block of d'cell as it is only about the samestrength as the styro.
The other alternative as 3mm corecell / divinycell etc over the top (to duplicate a normal deck) then put the track in.

If what we are seeing there is just the expanding foam, put a **** ton of glass over it, else the whole thing is doing to sink or roll. I'd say at least 8 layers of the 4ozcloth you had, fading out to 4 at the ede, and 2 overlapping the black deck by an inch or two.

Yes that white bit is the expanding foam with a little bit of q-cell/resin over it. Cr@p. I was worried about that. That was quite a bit of work, not to mention the cost of the materials. I guess I'll throw a few more layers of glass on it. If it blows out at that point, start over.